Appendix II. 863
Total energy = Potential energy + Kinetic energy, and
2
Total steam energy = (P x D) + w~
where w = weight of moving parts. Hence, as ordinates A M F B
shew total energy, and A L j B the load energy absorbed, the re
maining ordinates, by deduction, viz., those of A M K L, will indicate
kinetic energy of moving parts. Now,
*2L = K.E. /. v = V^y^ X/K.KX4I4
and V = VK.E. x 24*8
where energy is in foot tons, and w = 6 tons. Next, ordinates
K.E. are measured on A L K, and velocity curve found by calculation
The stroke will finish at P, directly under K, where v equals o ; and
the maximum velocity is at N, vertically over Q, where load and steam
curves cross. Cut off occurs at £% of stroke A P.
P. 492. Acceleration Curves.It was shewn at p. 492 how
to construct an acceleration curve to a distance base. The proof
will here be given by reference to Fig. 825. Let V be a velocity
ordinate, whose growth v in a small portion of time / takes place
at A; also let a small distance d be traversed during time /.
x T is a tangent to the curve, and A B a normal; then D B or x
will shew the acceleration fy for

J t d /
But  = velocity V, for space = tv
and ^ = . by similar triangles. Substituting
The construction cannot be reversed to find v, but \v^ may be
found by summation^ and V be therefrom deduced.
P. 496. Comparison of Angular Velocities in Link
work. In pp. 490496 are found the linear velocities of points in
linkwork. But it is often convenient to know the ratios of
angular velocities in a pair of links, and two cases will here